This invention relates to a monitoring system for a pneumatic conveying system.
Pneumatic conveying systems are widely used for transporting material (usually free-flowing) through conduits such as pipe or tubing. They may be used to transport material from truck or rail car or into storage, from storage to process, process to process, from process to storage, from process to truck or rail car, and from storage to truck or rail car. Many different types of systems are used, depending on the logistics of the application. The different types include vacuum driven systems, pressure driven systems, or combination vacuum/pressure systems. An air moving source, a conduit, an air inlet, a solids inlet, and a mixture outlet, are found in each type.
It is often necessary or desirable to provide a scaling system for the pneumatic conveying system. One type of scaling system employs a beam scale. In this type of scaling system, material is deposited into a hopper and weighed by a conventional beam scale. Another type of scaling system employs a belt scale, whereby material is passed over a belt with the speed of the belt and the deflection of the belt being measured, and the results calculated to determine the conveying rate and total material conveyed. In another known scaling system, the entire storage is placed on load cells, whereby the amount of material added to or subtracted from the storage results in a measurable displacement of the load cell. High and low level switches start and stop the transfer action automatically, or an operator watching the scale can start and stop the system as needed.
All of the above-described known scaling systems have disadvantages. In particular, these known scaling systems are expensive, require a considerable amount of space, involve dirt and dust problems, and require extensive maintenance.